/*
 *  $Id$
 */

/*
 * canplayer.c - replay a compact CAN frame logfile to CAN devices
 *
 * Copyright (c) 2002-2007 Volkswagen Group Electronic Research
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions, the following disclaimer and
 *    the referenced file 'COPYING'.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of Volkswagen nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * Alternatively, provided that this notice is retained in full, this
 * software may be distributed under the terms of the GNU General
 * Public License ("GPL") version 2 as distributed in the 'COPYING'
 * file from the main directory of the linux kernel source.
 *
 * The provided data structures and external interfaces from this code
 * are not restricted to be used by modules with a GPL compatible license.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 *
 * Send feedback to <socketcan-users@lists.berlios.de>
 *
 */

#include <stdio.h>
#include <string.h>
#include <time.h>
#include <libgen.h>
#include <stdlib.h>
#include <unistd.h>

#include <net/if.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <linux/can.h>
#include <linux/can/raw.h>

#include "lib.h"

#define DEFAULT_GAP 1 /* ms */
#define DEFAULT_LOOPS 1 /* only one replay */
#define CHANNELS 20   /* anyone using more than 20 CAN interfaces at a time? */
#define BUFSZ 100     /* for one line in the logfile */

struct assignment {
    char txif[IFNAMSIZ];
    int  txifidx;
    char rxif[IFNAMSIZ];
};
static struct assignment asgn[CHANNELS];

extern int optind, opterr, optopt;

void print_usage(char *prg)
{
    fprintf(stderr, "\nUsage: %s <options> [interface assignment]*\n\n", prg);
    fprintf(stderr, "Options:              -I <infile>  (default stdin)\n");
    fprintf(stderr, "                      -l <num>     "
	    "(process input file <num> times)\n"
	    "                                   "
	    "(Use 'i' for infinite loop - default: %d)\n", DEFAULT_LOOPS);
    fprintf(stderr, "                      -t           (ignore timestamps: "
	    "send frames immediately)\n");
    fprintf(stderr, "                      -g <ms>      (gap in milli "
	    "seconds - default: %d ms)\n", DEFAULT_GAP);
    fprintf(stderr, "                      -v           (verbose: print "
	    "sent CAN frames)\n\n");
    fprintf(stderr, "Interface assignment:  0..n assignments like "
	    "<write-if>=<log-if>\n");
    fprintf(stderr, "e.g. vcan2=can0 ( send frames received from can0 on "
	    "vcan2 )\n");
    fprintf(stderr, "No assignments => send frames to the interface(s) they "
	    "had been received from.\n\n");
}

/* copied from /usr/src/linux/include/linux/time.h ...
 * lhs < rhs:  return <0
 * lhs == rhs: return 0
 * lhs > rhs:  return >0
 */
static inline int timeval_compare(struct timeval *lhs, struct timeval *rhs)
{
    if (lhs->tv_sec < rhs->tv_sec)
	return -1;
    if (lhs->tv_sec > rhs->tv_sec)
	return 1;
    return lhs->tv_usec - rhs->tv_usec;
}

static inline int frames_to_send(struct timeval *today, struct timeval *diff,
				 struct timeval *log)
{
    /* return value <0 when log + diff < today */

    struct timeval cmp;

    cmp.tv_sec  = log->tv_sec  + diff->tv_sec;
    cmp.tv_usec = log->tv_usec + diff->tv_usec;

    if (cmp.tv_usec > 1000000) {
	cmp.tv_usec -= 1000000;
	cmp.tv_sec++;
    }

    return timeval_compare(&cmp, today);
}

int get_txidx(char *logif_name) {

    int i;

    for (i=0; i<CHANNELS; i++) {
	if (asgn[i].rxif[0] == 0) /* end of table content */
	    break;
	if (strcmp(asgn[i].rxif, logif_name) == 0) /* found device name */
	    break;
    }

    if ((i == CHANNELS) || (asgn[i].rxif[0] == 0))
	return 0; /* not found */

    return asgn[i].txifidx; /* return interface index */
}

char *get_txname(char *logif_name) {

    int i;

    for (i=0; i<CHANNELS; i++) {
	if (asgn[i].rxif[0] == 0) /* end of table content */
	    break;
	if (strcmp(asgn[i].rxif, logif_name) == 0) /* found device name */
	    break;
    }

    if ((i == CHANNELS) || (asgn[i].rxif[0] == 0))
	return 0; /* not found */

    return asgn[i].txif; /* return interface name */
}

int add_assignment(char *mode, int socket, char *txname, char *rxname,
		   int verbose) {

    struct ifreq ifr;
    int i;

    /* find free entry */
    for (i=0; i<CHANNELS; i++) {
	if (asgn[i].txif[0] == 0)
	    break;
    }

    if (i == CHANNELS) {
	fprintf(stderr, "Assignment table exceeded!\n");
	return 1;
    }

    if (strlen(txname) >= IFNAMSIZ) {
	fprintf(stderr, "write-if interface name '%s' too long!", txname);
	return 1;
    }
    strcpy(asgn[i].txif, txname);

    if (strlen(rxname) >= IFNAMSIZ) {
	fprintf(stderr, "log-if interface name '%s' too long!", rxname);
	return 1;
    }
    strcpy(asgn[i].rxif, rxname);

    strcpy(ifr.ifr_name, txname);
    if (ioctl(socket, SIOCGIFINDEX, &ifr) < 0) {
	perror("SIOCGIFINDEX");
	fprintf(stderr, "write-if interface name '%s' is wrong!\n", txname);
	return 1;
    }
    asgn[i].txifidx = ifr.ifr_ifindex;

    if (verbose > 1) /* use -v -v to see this */
	printf("added %s assignment: log-if=%s write-if=%s write-if-idx=%d\n",
	       mode, asgn[i].rxif, asgn[i].txif, asgn[i].txifidx);

    return 0;
}

int main(int argc, char **argv)
{
    static char buf[BUFSZ], device[BUFSZ], ascframe[BUFSZ];
    struct sockaddr_can addr;
    static struct can_frame frame;
    static struct timeval today_tv, log_tv, diff_tv;
    struct timespec sleep_ts;
    int s; /* CAN_RAW socket */
    FILE *infile = stdin;
    unsigned long gap = DEFAULT_GAP; 
    int use_timestamps = 1;
    static int verbose, opt, delay_loops;
    static int infinite_loops = 0;
    static int loops = DEFAULT_LOOPS;
    int assignments; /* assignments defined on the commandline */
    int txidx;       /* sendto() interface index */
    int eof, nbytes, i, j;

    while ((opt = getopt(argc, argv, "I:l:tg:v")) != -1) {
	switch (opt) {
	case 'I':
	    infile = fopen(optarg, "r");
	    if (!infile) {
		perror("infile");
		return 1;
	    }
	    break;

	case 'l':
	    if (optarg[0] == 'i')
		infinite_loops = 1;
	    else
		if (!(loops = atoi(optarg))) {
		    fprintf(stderr, "Invalid argument for option -l !\n");
		    return 1;
		}
	    break;

	case 't':
	    use_timestamps = 0;
	    break;

	case 'g':
	    gap = strtoul(optarg, NULL, 10);
	    break;

	case 'v':
	    verbose++;
	    break;

	default:
	    print_usage(basename(argv[0]));
	    return 1;
	    break;
	}
    }

    assignments = argc - optind; /* find real number of user assignments */

    if (infile == stdin) { /* no jokes with stdin */
	infinite_loops = 0;
	loops = 1;
    }

    if (verbose > 1) /* use -v -v to see this */
	if (infinite_loops)
	    printf("infinite_loops\n");
	else
	    printf("%d loops\n", loops);

    sleep_ts.tv_sec  =  gap / 1000;
    sleep_ts.tv_nsec = (gap % 1000) * 1000000;

    /* open socket */
    if ((s = socket(PF_CAN, SOCK_RAW, CAN_RAW)) < 0) {
	perror("socket");
	return 1;
    }

    addr.can_family  = AF_CAN;
    addr.can_ifindex = 0;

    /* disable unneeded default receive filter on this RAW socket */
    setsockopt(s, SOL_CAN_RAW, CAN_RAW_FILTER, NULL, 0);

    if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
	perror("bind");
	return 1;
    }

    if (assignments) {
	/* add & check user assginments from commandline */
	for (i=0; i<assignments; i++) {
	    if (strlen(argv[optind+i]) >= BUFSZ) {
		fprintf(stderr, "Assignment too long!\n");
		print_usage(basename(argv[0]));
		return 1;
	    }
	    strcpy(buf, argv[optind+i]);
	    for (j=0; j<BUFSZ; j++) { /* find '=' in assignment */
		if (buf[j] == '=')
		    break;
	    }
	    if (buf[j] != '=') {
		fprintf(stderr, "'=' missing in assignment!\n");
		print_usage(basename(argv[0]));
		return 1;
	    }
	    buf[j] = 0; /* cut string in two pieces */
	    if (add_assignment("user", s, &buf[0], &buf[j+1], verbose))
		return 1;
	}
    }

    while (infinite_loops || loops--) {

	if (infile != stdin)
	    rewind(infile); /* for each loop */

	if (verbose > 1) /* use -v -v to see this */
	    printf (">>>>>>>>> start reading file. remaining loops = %d\n", loops);

	if (!fgets(buf, BUFSZ-1, infile)) /* read first frame from logfile */
	    goto out; /* nothing to read */

	eof = 0;

	if (sscanf(buf, "(%ld.%ld) %s %s", &log_tv.tv_sec, &log_tv.tv_usec,
		   device, ascframe) != 4)
	    return 1;

	if (use_timestamps) { /* throttle sending due to logfile timestamps */

	    gettimeofday(&today_tv, NULL);

	    /* omit crazy comparations with negative diff_tv */
	    if (timeval_compare(&today_tv, &log_tv) < 1) {
		fprintf(stderr, "logfile timestamps newer than time of day!\n");
		return 1;
	    }

	    /* create diff_tv so that log_tv + diff_tv = today_tv */
	    diff_tv.tv_sec  = today_tv.tv_sec  - log_tv.tv_sec;
	    diff_tv.tv_usec = today_tv.tv_usec - log_tv.tv_usec;
	    if (diff_tv.tv_usec < 0)
		diff_tv.tv_sec--, diff_tv.tv_usec += 1000000;
	}

	while (!eof) {

	    while ((!use_timestamps) ||
		   (frames_to_send(&today_tv, &diff_tv, &log_tv) < 0)) {

		/* log_tv/device/ascframe are valid here */

		if (strlen(device) >= IFNAMSIZ) {
		    fprintf(stderr, "log interface name '%s' too long!", device);
		    return 1;
		}

		txidx = get_txidx(device); /* get ifindex for sending the frame */
 
		if ((!txidx) && (!assignments)) {
		    /* ifindex not found and no user assignments */
		    /* => assign this device automatically       */
		    if (add_assignment("auto", s, device, device, verbose))
			return 1;
		    txidx = get_txidx(device);
		}

		if (txidx) { /* only send to valid CAN devices */

		    if (parse_canframe(ascframe, &frame)) {
			fprintf(stderr, "wrong CAN frame format: '%s'!", ascframe);
			return 1;
		    }

		    addr.can_family  = AF_CAN;
		    addr.can_ifindex = txidx; /* send via this interface */
 
		    nbytes = sendto(s, &frame, sizeof(struct can_frame), 0,
				    (struct sockaddr*)&addr, sizeof(addr));

		    if (nbytes != sizeof(struct can_frame)) {
			perror("sendto");
			return 1;
		    }

		    if (verbose) {
			printf("%s (%s) ", get_txname(device), device);
			fprint_long_canframe(stdout, &frame, "\n", 1);
		    }
		}

		/* read next frame from logfile */
		if (!fgets(buf, BUFSZ-1, infile)) {
		    eof = 1; /* this file is completely processed */
		    break;
		}

		if (sscanf(buf, "(%ld.%ld) %s %s", &log_tv.tv_sec, &log_tv.tv_usec,
			   device, ascframe) != 4)
		    return 1;

		if (use_timestamps) /* save a syscall if possible */
		    gettimeofday(&today_tv, NULL);

	    } /* while frames_to_send ... */

	    if (nanosleep(&sleep_ts, NULL))
		return 1;

	    delay_loops++; /* private statistics */
	    gettimeofday(&today_tv, NULL);

	} /* while (!eof) */

    } /* while (infinite_loops || loops--) */

 out:

    close(s);
    fclose(infile);

    if (verbose > 1) /* use -v -v to see this */
	printf("%d delay_loops\n", delay_loops);

    return 0;
}
